This invention has particular application to dual wheels as exist on large trucks. However, as will be made clear, different forms of the invention can be applied to different types of vehicle wheels.
The invention is considered most applicable to large trucks driven by truck drivers that crisscross the country continuously throughout the year. Invariably a truck driver driving over mountain roads in the winter or even flat land roads in the Northern states, will on many occasions encounter road conditions where snow and/or ice is coated over the road surface.
The conventional wheel tire provides a road contacting surface area that frictionally grips a dry or even wet road surface providing steering and stopping control as well as propulsion over the road surface, but not when that surface is covered with ice and/or snow. The conventional tire surface has poor frictional gripping capability when riding on snow or ice. Whereas several explanations can be given depending on the condition of the ice/snow, what can and often does happen is that the surface of the snow or ice liquefies and forms a liquid film between the tires and underlying surface, thereby eliminating any opportunity for the tire to grip the surface frictionally.
An answer to this dilemma is to provide the tire with metal studs or chains. The studs are embedded in the tire permanently and the chains are designed to be placed on the tire when needed and removed when not needed. In both cases, the projecting metal bites down through the snow or ice (and liquid film) to generate the desired gripping action. Both have problems. Studded tires tear up a dry road surface, i.e., when not covered with snow or ice and most states have strict rules about using them. Most states ban their use except during the harsh winter months. Tire chains are designed to be put on and taken off. However, mounting the chains onto the vehicle tires is an unpleasant task even in ideal conditions which most often is not the case. Weather conditions are likely uncomfortably cold and blustery. Mounting the chains onto the tires can take upwards to an hour or more, and when parked alongside an ice-covered roadway and probably on a graded road, the driver is exposed to potential life threatening risks as other unchained vehicles attempt to pass.